Why will Walpole to Grimsby electricity line be overhead and not underground?

National Grid has outlined why it is proposing an overhead electricity line between Walpole and Grimsby in Lincolnshire, and not underground or sub-sea alternative connections.

It is carrying out its second consultation, this time legally required, on the proposed 140km pylon line. There is a more detailed route proposal with some changes brought in after public feedback last time.

The consultation is open until August 6, with a number of in-person events and webinars planned too. Opposition to the proposed pylon line was strong last year, some MPs calling for parts of it to be made up of underground cables.

The LDRS asked National Grid whether it had considered putting part of the line underground, and if it had, why these were not in the latest proposals.

A spokesperson said: “National Grid is proposing an overhead line for the Grimsby to Walpole route in line with Government planning policy which sets overhead lines using pylons as the preferred option for new electricity transmission projects.

“While underground cables have been considered, an overhead line offers the most efficient, reliable and cost-effective way to deliver the home-grown British energy which will lower our electricity bills in the long-term and make us more energy independent.”

National Grid provided cost estimates it had for different ways to create the new electricity connection it is proposing with the pylon line.

The AC pylon line would cost £1.6billion. The estimated cheapest alternative would be an HVDC subsea cable at £4.2billion.

A HVDC underground cable would cost £4.76billion, and an AC underground cable £7.1billion.

The pylon line forms part of National Grid’s The Great Grid Upgrade, the biggest investment in the electricity network in Britain for a generation.

It states they are vital upgrades to meet growing demands for electricity.

National Grid currently plans, subject to planning consent beforehand, to have the pylon line operational in 2033.

To learn more about the consultation and how to get involved, members of the public can visit the project’s website at nationalgrid.com/g-w